diff --git a/pyproject.toml b/pyproject.toml
index 67472f71..0262e3a8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "snooty"
-version = "0.18.9"
+version = "0.18.9.dev"
 description = ""
 authors = ["MongoDB, inc. <andrew.aldridge@mongodb.com>"]
 license = "Apache-2.0"
diff --git a/snooty/__init__.py b/snooty/__init__.py
index 702792b8..039e1422 100644
--- a/snooty/__init__.py
+++ b/snooty/__init__.py
@@ -1,3 +1,3 @@
 """The Snooty documentation writer's tool."""
 
-__version__ = "0.18.9"
+__version__ = "0.18.9.dev"